Hundreds of passengers were reported injured in downtown Shanghai on Tuesday after a subway train rear-ended another, sparking renewed public anger over China's blemished safety record.
The accident came just two months after a July high-speed rail crash killed at least 40 people, amid widespread outrage at official handling of the disaster.
The crash occurred about at 2:51 p.m. local time, and was initially blamed on "signal failure," the same cause cited for July 23's high-speed train crash in Wenzhou.
Around 500 passengers were evacuated from the trains, operator Shanghai Shentong Metro Group said in a statement.
The crash came as staff struggled to direct the trains by telephone, following a failure of the signaling system, it said.
Official media estimated the number of injured in Tuesday's crash at 271.
The official Xinhua news agency quoted doctors as saying that most of the injuries were bruises and bone fractures.
While there were some cases of external head trauma, no one was reported to be in critical condition, it said.
Video posted online of the aftermath of the crash showed dozens of firefighters helping injured people outside the Yuyuan Garden Station on Line 10 of the city's subway system.
Yuyuan Garden is a major tourist attraction in central Shanghai.
A number of the injured lay on stretchers on the ground as bystanders gathered, some making anxious phone calls, while others took photos and video.
Doctors told Xinhua that most of the injuries were bruises and bone fractures.
Shanghai Shentong Metro apologized on Tuesday via the popular Sina Weibo microblogging service.
"Today was the darkest day in the history of the Shanghai Metro," the company said via its official account on Weibo.
"Regardless of where the final cause or responsibility is found to lie, we feel guilty and ashamed at the injuries and damage caused to passengers and citizens," the update said.
"We will do everything in our power to rescue the injured and return to normal operations, as well as cooperate with relevant departments in their investigations and pursuit of those responsible."
The company halted subway services at nine stations on Line 10 following the accident.
Like the Wenzhou high-speed rail crash, the Shanghai metro crash sparked widespread popular anger online.
"So irresponsible," commented a user identified by a cell phone number, while user @didiaobixudi added, "Thank goodness those people were OK. Now they must find out the reason and make improvements."
"Call your Party Secretary out to admit his guilt," wrote user @boshidunzuijiaduju. "You had better start learning from the Japanese."
User @huba_Michael_xuzhibin retorted sarcastically: "How very moving, but not as moving as July 23. Apart from this verbal apology, when are the bosses of Shanghai Metro planning to commit harikiri [ritual suicide]?"
In interviews with Agence France-Presse, passengers described being flung against internal poles and losing balance as the moving train came to a rapid stop.
"This accident shouldn't have happened," Wen Pei, a passenger in the emergency room of Shanghai's Ruijin Hospital told the agency.
Officials said 260 people had been sent to hospital following the crash. The government has set up an investigative team to probe the cause of the accident.
Line 10 was open again and running normally within hours of the crash, Shanghai Shentong Metro said.
But Shanghai-based rights lawyer Li Tiantian said the authorities appear to be in too much of a hurry to get services running normally again.
"There's no need, when there are also buses that can substitute for trains," she said. "Either way, ordinary people don't get a say."
She said the crash had come as a shock to Shanghainese, who are renowned for their focus on economic priorities.
"People in Shanghai are the least likely to pay attention to their government," Li said. "Perhaps this will come as a warning [to them]."
Reported by Ho Shan and Bi Zimo for RFA's Cantonese service and by Ding Xiao for the Mandarin service. Translated and written in English by Luisetta Mudie